1. Field of the Invention
This invention relates to a method of manufacturing an optical compensator plate, and more particularly to a method of manufacturing an optical compensator plate having a negative optical anisotropy or activity.
2. Description of the Related Art
An optical compensator is an optical component having an optical anisotropy, used for compensating the optical anisotropy of another optical component of interest.
Liquid crystal molecules used in such devices as liquid crystal display devices ordinarily have an elongated shape, have a high refractive index in the direction parallel to the molecular axis and a low refractive index in directions perpendicular to the molecular axis.
When such liquid crystal molecules are oriented perpendicular to the substrate between a pair of transparent substrates, the liquid crystal cell will show a positive optical anisotropy. Performance of the liquid crystal cell in this state depends primarily on the angle measured from the normal of the substrates.
For compensating this positive optical anisotropy, there is needed a material having a negative optical anisotropy having a low refractive index in the direction of thickness, and a high refractive index in the directions in the plane. Further, it is necessary to adjust the degree of optical anisotropy .DELTA.n.multidot.d of the optical compensator plate, where .DELTA.n=n.sub.0 -n.sub.e, n is the refractive index, n.sub.0 is the refractive index for the ordinary ray, and n.sub.e is the refractive index for the extraordinary ray, and d is the thickness of the compensator plate, in accordance with the degree of the optical anisotropy to be compensated. However, it is not easy to manufacture an optical medium having the desired optical properties.